You need to find something on or close to Sepulveda Blvd--or if you don't mind spending a bit more, something in Santa Monica on Santa Monica Blvd.

I suggest something near Marina del Rey or Venice Beach or in Santa Monica. Stay out of Culver City, Hawthorne, El Segundo and especially stay out of Inglewood main area.

I suggest the following two hotels--Venice Beach Suites and Hotel (fairly reasonable for being pretty much right at the beach--but it is a little bit off the bus routes)--or this fairly upscale area)--around $139/night or the Marina del Rey Hotel--around $135/night. If you are looking for cheaper than this, the two I suggest you try are the Comfort Inn and Suites at LAX (around $85/night), or cheaper yet, the Value Inn Worldwide LAX--which is just barely in Inglewood, but is $65 per night.

P.S. I've got to tell you now--Los Angeles without a car is a major nightmare. Spending an extra $35-40 per day or so on a rental is well worth the cost versus the headaches you will go through--and the extra costs incurred--if you don't have a car. I lived in LA for over 25 years and I would never go back there if I had to get around by public transportation--even if it was only for 1 day.